Denji is a teenager who lives his life as a Devil Hunter.

Aiming to pay off the debt he inherited from his father, he starts hunting devils for the yakuza with his buddy Pochita, a "Chainsaw Devil", while living a tragically poor life.

Just when things seem like they couldn't get any worse, Denji gets betrayed and killed by the yakuza. As Denji starts passing out, he hears someone calling from inside his head...
If that's something you can do... 
then I want you to have my body.
إذا كان هناك ما تستطيع فعله... فأريدك
أن تستحوذ على جسدي
En caso de que tú puedas hacer eso…
Si tú puedes hacerlo,
Se anche tu puoi farlo,
Se você conseguir fazer isso,
quero dar meu corpo a você.
Если тоже так умеешь, Потита…